At inauguration, Pope Francis appeals for protection of poor, environment

Eager crowds greeted Pope Francis in St. Peter's Square, where he described the importance of helping the poor and the weak. NBC's Anne Thompson reports.

By Claudio Lavanga and Alastair Jamieson, NBC News

Pope Francis issued an appeal for the protection of the weak, the poor and the world environment Tuesday at a special Mass marking his inauguration as the new leader of the world's 1.2 billion Roman Catholics.

During the homily, he told a crowd of up to 200,000 gathered in front of the Vatican: “I would like to ask all those who have positions of responsibility in economic, political and social life, and all men and women of goodwill: Let us be protectors of creation, protectors of God’s plan inscribed in nature, protectors of one another and of the environment.”

He added: “We must not be afraid of goodness or even tenderness.”

There was a ripple of applause through a packed St. Peter's Square, and tears in the eyes of the some of the faithful, as Francis spoke of humility and the need for advocacy on behalf of the poor – themes he has already established as the hallmarks of his papacy.

“Let us never forget that authentic power is service,” he said. “Only those who serve with love are able to protect.”

The pope defined his idea of protection as “respecting each of God’s creatures and respecting the environment in which we live.” He said:

It means protecting people, showing loving concern for each and every person, especially children, the elderly, those in need, who are often the last we think about. It means caring for one another in our families: Husbands and wives first protect one another, and then, as parents, they care for their children, and children themselves, in time, protect their parents. It means building sincere friendships in which we protect one another in trust, respect, and goodness. In the end, everything has been entrusted to our protection, and all of us are responsible for it. Be protectors of God’s gifts!

NBC Vatican analyst George Weigel said the pope’s message was that “one should never confuse simplicity and humility with weakness.”

A formal procession to the steps of St. Peter’s Basilica was followed by the formal presentation to Francis of the pallium - a lamb’s wool scarf symbolizing Jesus as the good shepherd - and the fisherman’s ring, a specially cast, gold-plated silver symbol of St. Peter’s role as a fisherman.

Vatican chief spokesman, the Rev. Federico Lombardi, said an estimated 150,000 to 200,000 were in St. Peter's Square.

Before the ceremony began, some ran to secure the best viewing spots when space was opened up on a first-come-first-served basis.

"We are originally from Argentina and we wanted to be here today because Pope Francis is from our home town. We were so proud when he was elected. We travelled overnight so we could be here today," Cirigliano Valetin, 51, an electrician who works in Salerno in southern Italy told Reuters.

"He is a simple, humble person, he is not like the untouchable popes, he seems like someone normal people can reach out to," said Valetin, who is originally from Buenos Aires.

The first pontiff from the Americas, Francis has already made it clear he intends to adopt a simpler and more modest style at the Vatican – a move reflected in Tuesday’s ceremony which is shorter than that of his predecessor, Pope Benedict XVI, in 2005.

NBC News Special Report: NBC's Keir Simmons and Father Robert Barron report from St. Peter's Square in Vatican City, where pilgrims and faithful celebrate Pope Francis' inaugural mass.

On Wednesday, Francis will receive more than 30 delegations representing other Christian churches, as well as the Jewish, Muslim, Buddhist, Sikh and Jain religions, a Vatican spokesman said.

He will address foreign ambassadors to the Vatican on Friday and have lunch with Benedict -- their first meeting since the conclave and the first of its kind in modern times -- on Saturday before leading celebrations the next day for Palm Sunday, the first day of Holy Week leading to Easter.